TELE-TECH & - AmericanRadioHistory.Com

FREED
OFFERS FOR IMMEDIATE
DELIVERY FROM STOCK
MIL -T -27 STANDARD
POWER, FILAMENT, PULSE
\s and AUDIO TRANSFORMERS
POWER TRANSFORMERS
Filament Filament
#1 #2
Hi .. - ., .4 MIL
Cat. Volt c = 2,É É - E Case
No. Sec. et . e s as Size
400/200 V 185 .070 6.3/5 2 6.3 3 H11
4 Jr
2
MGP1
MGP2 650 V 260 .070 6.3/5 6.3
MGP3 650 V 245 .150 6.3 5 5.0 3 KB
MGP4 800 V 318 .175 5.0 3 6.3 B LB
MGM 900 V 345 .250 5.0 3 6.3 e MB
MOPE 700 V 255 .250 KB
MGP7 1100 V 419 .250 LB
MGPB 1600 V 640 .250 NB
FILAMENT TRANSFORMERS
Cat. Secondary Test MIL
No. Volt Amp VRMS Case
MGF1 2.5 3.0 2,500 EB
MGF2 2.5 10.0 2,500 GB
MGF3 5.0 3.0 2,500 FB
MGF4 5.0 10.0 2,500 HB
MGF5 6.3 2.0 ' 2,500 FB
MGF6 6.3 5.0 2,500 GB
MGF7 6.3 10.0 2,500 JB
MGF8 6.3 20.0 2,500 KB
MGF9 2.5 10.0 10,000 JB
MGFIO 5.0 10.0 10,000 KB
ug
e_
s:O
PULSE
Pulsa
Voltage
Kilovolts
TRANSFORMERS
- E.
eM '
2
e
M
ó -
s° e-
MPT1 V V 0.25/0.25/0.25 03.1.0 .004 3 0.7 250
MPT2 V V 0.25/0.25 02.1.0 .004 2 0.7 250
MPT3 V V 0.5/0.5/0.5 0.2.1.5 .002 3 1.0 250
MPT4 V V 0.5/0.5 0.2.1.5 .002 2 1.0 250
OPTS V V 0.5/0.5/0.5 0.5.2.0 .002 3 1.0 500
MPTO V V 0.5/0.5 0.5-2.0 .002 2 1.0 500
MPT7 V V 0.7/0.7/0.7 0.01.5 .002 3 1.5 200
OPTS V V V 0.7/0.7 0.5-1.5 .002 2 1.5 200
OPTO V V V 1.0/1.0/1.0 0.7.3.5 .002 3 2.0 200
MPT10 V V V 1.0/1.0 0.73.5 .002 2 2.0 200
Mn11 V V V 1.0/1.0/1.5 1.05.0 .002 3 2.0 500
MPT12 V V V 0.15/0.15/0.3/0.3 0.2.1.0 .004 4 0.7 700
AUDIO TRANSFORMERS
Frq.- na. 300 to 10000 .pe 2 3 011. All Case Silas Ll
z`
4111ut1u
EO
'
Imp.bno
corñot
if - a- -
:
É
=
4
33
;m
MMI 1.1"7.7.. t ïï ináL 10a v áó11t y 10 t0 +IS
Mw 1.122 t. Yoko Coll =Y°t ., 1.
NM]
11. t. 11f1 or
Pl.sns
10 0 0+33
Sw
apnt tu4 V 0 0 +If
LM. to UM blft pt
0 0
3n31. Plato to UM lj¡
NO
° 40 40 +as
Mw SIe31 Nato tS 0oM Cot 12 4,1414 40 40 +33
MLO %IrFlatt, t. LIM 1S4 V H0, IS 10 +13
Mw 0l. Platte to Um 344 V jjj t la 1+14
N. Wb to Lino S4 v
MO
llt 14 1 +27
Send for further information on these un ts, or
special designs. Also ask for comp ale
laboratory test instrument catalog.
FREED
TRANSFORMER CO., INC.
1726 WEIRFI ELD STREET
BROOKLYN IRIDGEWOOD) 27, N. Y.
Antenna Arrays
(Continued from page 207)
a. and It, = 4.65 a. assuming a power
input to the array of 1 kw. Hence
1.055 is equivalent to 5.45 a.
The array RMS field strength is
then (5.45/6.03) x 185.5 = 168 my /m
at one mile. See Fig. 3.
(d) An array of three 90° radiators
in line and spaced at 90° between
adjacent elements. IM (center
element) = 1.0 f Ib = 0.5 / -150
and I. = 0.5 / +150. From an impedance
analysis it is found that I.
= 4.90a. and Ib= Ic= 2.45a.The
pattern shape is derived from the
above and the RMS value in reference
units is 0.774. Hence 0.774 is
equivalent to 3.79 a.
A 90° radiator alone radiates 190
my /m at one mile, has a base impedance
of 55 +j85, and thus a base
current of 4.27 a. for 1 kw.
Therefore the array RMS in field
strength is (3.79/4.27) x 190 = 169
my /m at one mile. See Fig. 4.
Conclusion
It has been found in practice that
RMS predictions in accordance with
the foregoing procedure may be
confirmed in the field. Unfortunately,
no opportunity has arisen to
check the theory on arrays made up
of unequal height radiators. Therefore
the above statement for the
time being must be limited to only
arrays with equivalent elements.
In example (a), it is noted that
theoretically the array is more efficient
than a single element system.
A check on the vertical sections of
the pattern will, however, demonstrate
that this is perhaps not unrealistic
inasmuch as radiation
skyward from the major lobe is
compressed compared to an omni
array, and therefore higher efficiency
may be the case in practice.
For the other examples the results
are as expected and the pattern RMS
is of course somewhat less than for
a single element. This is due essentially
to the high degree of field cancellation
throughout a sizable portion
of the horizontal pattern.
The method outlined above for
the computation of AM pattern RMS
values has neglected the effects of
ground losses in a system. Certainly
these losses are an important consideration
and wherever possible
should be taken into account. Experience
is the best guide in this
instance, and it is suggested that the
inclusion of ground losses is a matter
of individual judgment.
450-470 MCS
152-174 MCS
the only
20 Ib.
high gain
antenna
highest gain antenna available-IO
db gain 450 -470 Ws
(6 db gain 152 -174 Mcs).
20 Ib. weight permits "one
man" installation -no crane
or crew needed.
Fiberglas* construction permanently
seals against
weather. Closed cellular core
eliminates internal moisture
problem.
guaranteed 100 MPH with 1/2"
radial ice load.
grounded structure minimizes
lightning hazard.
power capacity 250 watts
continuous.
termination -coaxial 50 ohms
nominal.
overall length approximately
15'.
write for engineering data
and patterns -Mark Products
Co., 6412 W. Lincoln Ave.,
Morton Grove, Illinois. Phone
ORchard 5 -4999.
MARK
PRODUCTS
company
OWE ..CONINING
FIBERGLAS
208 For product information, use inquiry card on pages 209-210.
Tele -Tech & ELECTRONIC INDUSTRIES June 1956